Zac Guildford has become the latest injured All Black at the World Cup after
pulling up lame in training, just as the team welcomed the return to fitness
of captain Richie McCaw.

Guildford, who scored four tries in his first World Cup outing against Canada last weekend, pulled a hamstring in training but the seriousness of the injury was not immediately clear.

"I just pulled up a bit short at training, we haven't assessed it yet," said Guildford, who had been hoping his starring role against Canada would put him in the frame for selection to play in Sunday's quarter-final against Argentina.

But the 22 year-old, who was publicly reprimanded by team management early in the tournament for excessive drinking, admitted there was "huge competition" for the two wing berths.

Unlike the loss of fly-half Dan Carter, now out of the World Cup with a tournament-ending groin injury, New Zealand have plenty of depth when it comes to their outside backs.

Richard Kahui and Cory Jane appear the likely starters, while coach Graham Henry has also experimented successfully with centre Sonny Bill Williams on the wing and Israel Dagg and Isaia Toeava have experience there.

Colin Slade is expected to start at fly-half against Argentina with scrum-half Piri Weepu as his back-up, while Carter's replacement Aaron Cruden is now training with the squad but unsure if he will get any game time.

Cruden, who appeared in six Tests last year before slipping behind Slade in the pecking order, said his initial focus was to get up to speed with the All Blacks' plays.

"I'm not to sure what the playing side of it is going to be," he said, adding the message from backs coach Wayne Smith was to "play my natural game if given the opportunity and just prepare as I normally do thoughout the week".